BORIS JOHNSON has put Britain on lockdown for three weeks after his pleas for the country to stay at home were ignored.

The Prime Minister imposed the most draconian measures the UK has faced in peacetime as the death toll continued to rocket. Mr Johnson told the public the nation is facing a national emergency and they must stay at home to save lives.

Police will enforce the lockdown by breaking up groups and imposing fines of £30 upwards on people who flout the rules.

Speaking in Downing Street, the PM said the only valid reasons for venturing outside were to buy food, carry out essential work or for medical reasons.

One outdoor trip for exercise each day is also allowed but there should be no more than two people together in public, except for members of the same household.

All non-essential shops have been ordered to shut down, weddings cancelled and religious gatherings banned.

Mr Johnson thanked the “huge numbers” of Britons who have complied with the government’s advice so far but said “the time has now come for us all to do more”.

“From this evening I must give the British people a very simple instruction – you must stay at home,” he said.

“Because the critical thing we must do is stop the disease spreading between households.

“That is why people will only be allowed to leave their home for the following very limited purposes – shopping for basic necessities, as infrequently as possible, one form of exercise a day – for example a run, walk, or cycle – alone or with members of your household, any medical need, to provide care or to help a vulnerable person; and travelling to and from work, but only where this is absolutely necessary and cannot be done from home.

That’s all – these are the only reasons you should leave your home.

“You should not be meeting friends. If your friends ask you to meet, you should say No.

“You should not be meeting family members who do not live in your home.

“You should not be going shopping except for essentials like food and medicine — and you should do this as little as you can. And use food delivery services where you can.

“If you don’t follow the rules the police will have the powers to enforce them, including through fines and dispersing gatherings.”

Mr Johnson said no Prime Minister wanted to impose such measures and insisted he understood the damage it is doing to people’s lives, businesses and jobs.

“And I can assure you that we will keep these restrictions under constant review,” he added. “We will look again in three weeks, and relax them if the evidence shows we are able to.”

“But at present there are just no easy options. The way ahead is hard, and it is still true that many lives will sadly be lost.

Mr Johnson insisted there was a “clear way through” and he believed the “people of this country will rise to that challenge”.

“We will beat the coronavirus and we will beat it together.

“And therefore I urge you at this moment of national emergency to stay at home, protect our NHS and save lives.”

Mr Johnson had issued a final warning to the nation on Sunday after crowds flocked to beaches and parks.

But Britons continued to gather outdoors yesterday (MON) and queue at shops. Tube carriages in London, the coronavirus hotspot, remained packed.

The PM chaired a meeting of the Cobra emergency committee at 5pm to discuss the lockdown after facing intense pressure to take tougher action.

The new measures were imposed as the number of people with the Covid 19 virus who have died in the UK reached 335.